The present invention relates to a sensor for use with a spectral analyzer for living tissues. The sensor is capable of obtaining data in a timely manner at constant pressure and can be handled easily with increased safety and reliability.
Spectral analysis of living tissues (the stomach, intestines, skins, tooth sockets and other parts of the living organism) is conventionally performed by one of two methods: (1) the tip of a bundle of fibers connected to the spectral analyzer is inserted into the human body either directly or with the aid of a laparoscope or a fiberscope, and while the pressure applied to the tissue is controlled with one hand, the analyzer is switched on and off with the other hand to obtain data; and (2) the tip of bundle of fibers connected to the spectral analyzer is inserted into a spring-loaded holder in the form of an elongated tube with a contact provided between the holder and fiber bundle and connected to the switching circuit in the analyzer, and the holder is inserted in the human body until the fiber bundle whose tip is being pressed against the tissue is retracted by a predetermined distance against the force of the spring, whereupon the contact is closed to start the collection of the necessary data.
In the spectral analysis of living tissues, data must be obtained as soon as the tip of the bundle of fibers contacts the tissue and before any undesired change occurs in the living tissue, and the pressure applied to the tissue by the tip of the fiber bundle is desirably held constant to maintain the local hemostatic effect. These requirements are however not fully met by either of the two conventional methods. According to the first method, there often occurs a time lag in obtaining the necessary data because it is difficult to synchronize the timing of the setting of the tip of the bundled fiber on the tissue and that of switching on the analyzer. Furthermore, this method requires both hands of the operator and is not efficient, and the pressure applied to the tissue by manual control tends to fluctuate and to lack accuracy. In the second method, a bundle of relatively heavy fibers is moved in the holder against the force of the spring, so the pressure applied to the tissue changes substantially depending upon the angle at which the holder is set on the body part.